Area=pi times radius^2 so
if area=4pi=pi times r^2
4 times pi=r^2 times pi
divide both sdies by pi
4=r^2
square root
2=radius since legnth cannot be negative
radius=1/2 diamters
2 radius=diameter
2(2)=diameter=4
diameter=4
Answer:
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Answer:
4 stations
Step-by-step explanation:
If we need to be at least 98% certain that an enemy plane flying over will be detected by at least one station, we must ensure that there is at most a 2% chance that no radar stations detect the plane.
The probability that a single radar station does not detect the plane is 0.35.
For n radar stations:

Rounding up to the next whole station, at least 4 stations are needed.
Answer:
80% 0.8
Step-by-step explanation:
To find the percentage out of a fraction you would divide 4÷5 to get 0.8, the decimal answer, then to turn that to a percent you would move the point two places to the right to get 80%.
Answer:

Step-by-step explanation:
Using the Pythagorean identity
sin²x + cos²x = 1, then
sinx = 
Note that (
)² = 
sinΘ = 
=
= 